ADR 0110 and 0111: a seat is a module assignment from a closed set, and a build source may live on the git seat

Seats have been doing two jobs and neither is written down. The mechanism ADR 0009 introduced is
enforced — a second holder is refused — but any well-formed name becomes a seat by being claimed,
and nothing can say which seats a mesh has or who holds them: holdings are assembled while planning
and discarded. The enumeration done while preparing this missed the control plane's own manifest,
because core modules' manifests live in its repository rather than the catalogue.

0110 closes the set. Each seat has a name, a scope, what occupying it delivers, and the record that
made it one; a claim outside the set is refused. A seat is held by a module assignment, and what the
mesh knows about the holder is what it knows about that assignment — nothing is stored beside it. A
seat may deliver a provision, and then its holder answers for it among several providers: pin, then
the holder, then the only provider, then refused. That keeps 0009's "refused, never guessed": the
seat is the choice made once, mesh-wide, instead of a pin per consumer node. The first set is the
eleven seats already claimed plus 0109's npm-package-registry, so nothing in use is refused.

Two concepts — seats for exclusion, a new word for consumable singulars — was rejected: both mean
"this mesh's one X", and the overview a person wants is one list.

0111 gives the mesh a git seat and makes a build source one of two explicit forms: a repository on
the seat's holder, recorded by its path and cloned from wherever the holder runs at build time; or
an external URL, recorded and cloned exactly as given. Recognising self-hosted sources by matching
URLs against the forge's address was rejected — it fails in the one case it exists for, after the
forge moves. Credentials for private repositories are left undecided and said so.

Design: new to-be 26 (the seats); 23 gains the seat step in resolution; 18's source entry names
the two forms; the glossary's seat and provision entries say where they meet. 0109 is carried from
its own branch so every link here resolves.
This commit is contained in:
jochen
2026-09-25 20:33:14 +02:00
parent 59c93dcfe4
commit dbe100ca96
8 changed files with 403 additions and 9 deletions
+3 -2
View File
@@ -5,8 +5,9 @@ code:
- mesh-controller cmd/mesh-builder
- mesh-controller internal/builder
- mesh-catalog modules/builder
updated: 2026-09-21
updated: 2026-09-25
decisions:
- 02-DECISIONS/0111-a-build-source-is-on-the-git-seat-or-external.md
- 02-DECISIONS/0097-a-vendor-image-is-a-declared-build-input.md
- 02-DECISIONS/0096-an-upstream-image-is-copied-between-registries.md
- 02-DECISIONS/0091-a-mount-is-declared-three-ways.md
@@ -38,7 +39,7 @@ controller's again. The builder's whole responsibility is the middle.
| term | is |
|---|---|
| **source** | a repository, a path within it, and a ref — resolved to one commit ([ADR 0069](../../02-DECISIONS/0069-a-module-is-a-repository-and-a-path.md)) |
| **source** | a repository, a path within it, and a ref — resolved to one commit ([ADR 0069](../../02-DECISIONS/0069-a-module-is-a-repository-and-a-path.md)). The repository is either on the forge holding the `git` seat, recorded by its path there and cloned from wherever that forge runs at build time, or external, recorded and cloned exactly as given ([ADR 0111](../../02-DECISIONS/0111-a-build-source-is-on-the-git-seat-or-external.md)) |
| **recipe** | how *one* artifact is produced from that source |
| **toolchain** | what a recipe runs inside — a compiler, a runtime, the SDK |
| **artifact** | what a recipe produced, named by the digest of its content |